Latchbolt holdback for doorlocks



July 21, 1964 F. J. MCCONNELL LATCHBOLT HOLDBACK FOR DOORLOCKS Filed June 28, 1962 2 Sheets-Sheet 1 JNVENToR. FRHA/ J." Nc CoA/Mezz,

July 21, 1964 F. J. MCcoNNELL 3,141,320

LATcHBoLT HoLDBAcK Foa DooRLocKs Filed June 28, 1962 2 Sheets-Sheet 2 IN V EN TOR. Fl'vHA/A/ 7.- /Vc CoA/NELL United States Patent O 3,141,320 LATCHBLT HOLDBACK FOR DGRLOCKS Frank J. McConnell, New Britain, Conn., assigner to The American Hardware Corporation, New Britain, Conn., a corporation of Connecticut Fiied .lune 28, 1962, Ser. No. 205,915 '7 Claims. (Cl. 7150) This invention relates to novel latchbolt holdback means for door locks and more particularly to latchbolt holdback means for door locks of the mortise or rim type, the present invention constituting a modified embodiment of the latchbolt holdback means disclosed in the copending application of Morris P. Bellantuono, Serial No. 170,348, led February 1, 1962, and now Patent No. 3,129,579, issued April 21, 1964.

That class of door locks for which the latchbolt holdback means of the present invention is especially intended is Well known. Said locks generally comprise a casing which is adapted to be mortised into the free edge of a door or mounted on a face thereof adjacent said edge. A latchbolt is supported in said casing for reciprocable movement between a projected, latching position and a retracted, unlatched position and said latchbolt is usually spring-pressed toward its projected position wherein it is engageable with a keeper on the door frame to retain the door in closed position.

The casing also contains rollback means for retracting the latchbolt which are adapted for operation by inner and outer manually operable means, such as door knobs or the like, and means may also be provided for dogging the outer manually operable means against operation to prevent retraction of the latchbolt from the outer side of the door. In this case, means are generally provided in the casing for operation by a key-operated lock cylinder at the outer side of the door for releasing the dogging means or retracting the latchbolt -to permit opening of the door when the outer manually operable means is dogged against operation.

In many instances, it is necessary or desirable to provide means in such locks for holding the latchbolt in retracted position to prevent engagement thereof with the keeper and thus permit free opening and closing movements of the door. This is particularly true in locks designed for use on the doors of public buildings or the like which are subjected to frequent usage; not only does disablement of the latchbolt reduce wear and tear on the lock mechanism, but it also insures facile passage through the doorway, especially in the event of an emergency.

The cost of producing a door lock with a latchbolt holdback can be minimized if as many of the conventional parts of the lock as possible are utilized in the holdback mechanism and if any changes which are required in such parts to accommodate elements of the holdback mechanism do not destroy their function in the conventional door lock. In this way, the same basic parts may be used in the door lock whether or not it is provided with a latchbolt holdback feature, thus eiecting considerable savings in the cost of manufacture.

In door locks of the above-described type which include a key-operated lock cylinder for retracting the latchbolt or releasing the aforementioned dogging means from the outer side of the door, it is of considerable advantage to utilize parts of the key-operated mechanism in the holdback means, not only for reasons of economy, but also because the holdback means may then be key-controlled and therefore set or released only by persons possessing the proper key.

It is therefore the primary object of the present invention to provide extremely novel latchbolt holdback 3,l4l,320 Patented July 21, 1964 means for door locks and particularly for door locks of the above-described mortise or rirn type.

A further object of the invention is to provide latchbolt holdback means for such locks which may incorporate conventional parts of the lock mechanism and which necessitate only minor changes in such parts.

Another object of the present invention is to provide novel latchbolt holdback means which are adapted for operation by key-operated means normally provided in the lock for other purposes.

A still further object of the present invention is to provide a latchbolt holdback member which may be mounted on a regular part of the lock mechanism for operation thereby.

Another object of the present invention is to provide latchbolt holdback means which operate in a novel and unusual manner.

A further object of the invention is to provide latchbolt holdback means for door locks which may be controlled by a key to prevent unauthorized operation thereof.

The foregoing and other objects and advantages of the invention will become apparent to those skilled in the art from the following description taken in connection with the accompanying drawings, which, by way of preferred example only, illustrate one specific embodiment of the invention.

In the drawings:

FIG. 1 is an elevational side view of a conventional mortise lock embodying my novel latchbolt holdback means, shown with the cover plate of the lock removed and illustrating the parts thereof in one of the positions which they may occupy.

FIG. 2 is a similar view illustrating the parts of the lock when the latchbolt holdback means is in latchbolt holdback position.

FIG. 3 is an exploded isometric view illustrating the latchbolt holdback member of the present invention and some of the conventional parts of the lock mechanism with which it is associated.

FIG. 4 is a sectional plan view of the lock taken on line 4--4 of FIG. 1.

FIG. 5 is a fragmentary elevational side view illustrating my novel latchbolt holdback means in a different position from that shown in FIG. 1.

FIG. 6 is a similar view illustrating the manner in which the latchbolt holdback member is set when the holdback mechanism is in the position shown in FIG. 5.

The door lock in which I have chosen to illustrate my novel latchbolt holdback means is of the conventional mortise type well known to those skilled in the art and I have therefore illustrated only those parts of the lock which are germane to the present invention.

Referring noW to FIGS. 1 and 4 of the drawings, the numeral 5 denotes the casing of the lock which is of generally rectangular shape and includes spaced, parallel, inner and outer sidewalls S-a and 5-b, respectively, and an end wall 5-c. In the casing shown, the end wall 5-c is integral with the outer sidewall S-b and contiguous to the upper, lower and rear edges thereof, and the sidewall S-a is in the form of a separate plate which is detachably secured against the edge of the wall S-c by screws, not shown, and forms a cover plate for the lock mechanism as illustrated in FIG. 4. The casing also includes a face plate 6 which overlies the open, forward edge thereof and is provided with a longitudinally extending rectangular opening l therein.

It will be understood by those skilled in the art that the casing is adapted to be mounted in a mortise formed in the edge of a door with the face plate 6 disposed flush with said edge, and that the casing is secured in the door by screws which extend through holes, not shown, in the opposite end portions of said face plate.

The casing 5 contains a conventional lock mechanism which includes a latchbolt 25 that is mounted in said casing for reciprocable sliding movement between a forward, projected position and a rearward, retracted position as shown in FIGS. 1 and 2, respectively. The latchbolt includes a head portion S-cz which extends through and is slidably guided in the opening 7 in the face plate t5 and is provided at its outer end with a bevelled camming face S-b for engagement with a keeper on the door frame, not shown. The latchbolt also includes an elongated tailpiece 9 which extends axially rearwardly from the head portion S-a and is slidably guided in a bifurcated lug 10 projecting from the outer sidewall 5-b of the lock case. The latchbolt is biased forwardly toward its normal projected position, as shown in FIG. l, by a compression spring 11 which surrounds the tailpiece 9 and is disposed between the lug 1t) and the rear end of the latchbolt head S-a.

The latchbolt S may be moved rearwardly from its normal projected position to its retracted position through the operation of conventional retracting means indicated generally by the numeral 12 in FIG. l. Said means include a latchbolt retracting lever 13 which is pivoted at its lower end on the lock casing and at its upper end is engageable with the free lower end of an auxiliary retracting lever 14. Said free end of the lever 14 is, in turn, engageable with a forwardly facing abutment surface 15-a on a foot 15 that is al'llxed to the rear end of the tailpiece 9 The retracting lever 13 is adapted to be actuated by a pair of rollbacks, such as the rollback 16 shown in FIG. l, which are mounted coaxially between the sidewalls of the casing 5 for independent, relative rotation in opposite directions. Each of the rollbacks has an axial bore 17 of polygonal cross-sectional shape for the reception of one part of a two-part spindle of complementary shape, not shown, adapted to carry door knobs or the like at its inner and outer ends. The rollbacks are arranged to actuate the retracting lever 13 either directly or through a secondary retracting lever 18 as best shown in FIG. 1. Thus, when the inner or outer knob is rotated in either direction, its respective rollback is also rotated and the lever 13 is pivoted in a counterclockwise direction, as viewed in FIG. 1. The resulting rearward movement of the free end of the lever 13 will be transmitted to the foot 15 through the auxiliary retracting lever 14 and the latchbolt will be moved rearwardly from its normal projected position to its retracted position shown in FIG. 2, such rearward movement being limited through engagement of the foot 15 with the endwall S-c of the casing.

The lock mechanism illustrated herein, in which I have chosen to show my novel latchbolt holdback means, includes a conventional dogging mechanism for selectively dogging the outer rollback against operation to prevent retraction of the latchbolt from the outer side of the door. Said lock mechanism is also provided with conventional retracting means actuatable by a key-operated lock cylinder for retracting the latchbolt from the outer side of the door when the outer rollback is rendered inoperable. The dogging mechanism employed in the illustrated lock is also adapted to be controlled by said lock cylinder, but since said clogging mechanism is old in the art, I have shown only those parts thereof which are related to the present invention.

The key-operated retracting means provided in the illustrated lock mechanism for retracting the latchbolt from the outer side of the door when the outer rollback is dogged against operation include the aforementioned auxiliary retracting lever 14. Said lever is pivotally mounted on a stud 19 which is atlixed to the outer sidewall S-b of the lock casing above the latchbolt and extends perpendicularly inwardly therefrom. At its upper end, the auxiliary retracting lever 14 is provided with a linger 14-1 which extends perpendicularly inwardly therefrom and is engageable by the free end of a cam 2t) which is secured to the inner end of a rotatable key plug 21 forming part of a conventional lock cylinder 22 that is threaded into a threaded opening in the outer sidewall of the lock casing. Thus, when the key plug 21 is rotated by the proper key in a counterclockwise direction, as viewed in FIG. l, the free end of the cam 20 engages the linger 14-a on the auxiliary retracting lever 14 and pivots the lever in a clockwise direction about the stud 19 to effect retraction of the latchbolt through engagement of the lower end of said lever with the abutment surface 15-a on the foot 15 as will be understood from FIG. l of the drawing.

The key operated cam 21B may also be used to move the dogging mechanism, not shown in its entirety, into and out of dogging position from the outer side of the door. To this end, the dogging mechanism includes a rocker member 23 which is mounted on the stud 19 inwardly of the auxiliary retracting lever 14 for pivotal movement in opposite directions about an axis normal to the longitudinal axis of the latchbolt. The rocker member 23 is of generally U-shaped configuration and comprises a substantially flat body portion 24 having a pair of arms 25 and 26 extending upwardly therefrom in spaced and diverging relationship. The body portion has coaxial bosses formed integrally on the opposite sides thereof at approximately its juncture with the arms 26, and a hole 27 extends therethrough on an axis normal to the plane of said body portion for the reception of said stud 19. The free end portions of the arms 25 and 26 have pads 28 and 29, respectively, formed thereon which extend transversely and to the opposite sides of said arms and have opposed, concave faces.

Pivotal movement of the rocker member 23 is limited through engagement of said arms Z5 and 26 with spaced stop pins 30 and 31, respectively, which extend perpendicularly inwardly from the outer sidewall of the lock casing. The rocker member is biased toward one or the other of said pins by a double acting leaf spring 32 which rests against the endwall of the lock casing and is provided with a yieldable leg 32-a having a detent portion 33 engageable with the free end portion of the arm 26 on said rocker member.

When the rocker member 23 is in its extreme left-hand position, illustrated in FIG. l, the dogging means controlled thereby is in dogging position and retraction of the latchbolt from the outer side of the door can only be accomplished through key operation of the cam 20, the concave face of the pad 29 on said arm 26 providing clearance to permit free movement of the cam into operative engagement with the auxiliary retracting lever 14 as above-described. When the rocker member is in its extreme right-hand position, shown in FIG. 5, the dogging means for the outer rollback is rendered ineffective, thus permitting retraction of the latchbolt from the outer side of the door through operation of the outer door knob or the like. The rocker member may be moved to either of its extreme positions by rotating the cam 20 into engagement with the respective arm 25 or 26, and is maintained in the selected position by the spring 32 as will be evident from the drawings.

I have provided by my invention latchbolt holdback means which are especially adapted for use in door locks of the abovedescribed type for holding the latchbolt in retracted position to permit free opening and closing movements of the door. As an extremely novel feature of my invention, I utilize the pivoted rocker member 23 of the lock mechanism as a carrier for the latchbolt holdback member and as a means for effecting movement of said latchbolt holdback member into and out of latchbolt holdback position through key operation of the cam 20. The latchbolt holdback means of my invention may be incorporated in the lock shown with very few structural changes and those changes which are necessary do not affect the function of the parts involved in the conventional lock mechanism.

The latchbolt holdback means of the present invention includes a latchbolt holdback member 34 which is preferably formed from sheet metal and includes a substantially at, elongated body portion 35 having an aperture 36 extending therethrough intermediate its ends. At its forward end, the body portion 35 is provided with a perpendicularly extending ear 37 forming an anchoring portion for one end of a spring as will be hereinafter described. At its rearward end, the body portion includes an integral finger 38 which extends downwardly therefrom at an obtuse angle and has a free end portion 39 containing a rearwardly facing stop surface 39-a. The lower edge of said nger 38 is formed to provide a pair of cam surfaces 40 and 40-a, respectively, the cam surface 4t) being disposed at a relatively steep angle with respect to the remainder of the body portion and the cam suurface 40-1 lying at a somewhat lesser angle and extending from the lower end of the cam surface 4i) to the end of said finger.

The latchbolt holdback member 34 is pivotally mounted on the lower portion of the rocker member 23 in radially spaced relation to its pivotal axis by a pivot pin 41 for movement in a plane parallel to the body portion of said rocker member about an axis extending perpendicularly Vthereto and to the axis of the latchbolt S. The pivot pin 41 is provided with a journal portion 42 sized to fit the aperture 36 in the latchbolt holdback member and an end portion 43 of reduced diameter which extends through a complementary opening 44 in the body portion of said rocker and is swaged thereover. The pivot pin is also provided with an enlarged head 45 which retains the latchbolt holdback member thereon, all as clearly shown in FIGS. l and 3 of the drawings.

The latchbolt holdback member 34 is guided into and out of latchbolt holdback position by a guide member in the form of a stud 46 which extends perpendicularly inwardly from the outer sidewall of the lock casing and is engageable by the cam surface 40 provided on said holdback member. Said cam surface is biased toward the periphery of said stud by a tension spring 47 which is secured at one end to the stop pin 30 and at its opposite end to the ear 37 on said latchbolt holdback member and yieldingly urges said member in a counterclockwise direction about the pivot pin 41.

With reference to FIG. 1 of the drawing, it will be seen that when the rocker member 23 is in its extreme left-hand position, as determined by the stop pin 31, the latchbolt holdback member 34 is retained out of latchbolt holdback position through engagement of the cam surface 40 thereon with the periphery of the stud 46. In this position, the free end portion 39 of the latchbolt holdback member is disposed out of the path of the foot 15 on the latchbolt, thus permitting unhindered retraction and projection of the latchbolt incident to normal operation of the lock mechanism. In addition, the arm 26 of said rocker member is disposed out of the path of the free end of the cam 20 so that the latchbolt may be retracted through key operation of the auxiliary retracting lever 14 from the outer side of the door without interfering with the latchbolt holdback means.

When it is desired to maintain the latchbolt in retracted position to permit free opening and closing movements of the door, it is only necessary to move the latchbolt to its fully retracted position, as indicated in FIG. 2, either by manual depression thereof or by operation of the rollback means 12 from the inner side of the door. The key plug 21 of the lock cylinder 22 is then rotated in a clockwise direction, as viewed in FIG. 2, to cause clockwise movement of the rocker member 23 through engagement of the free end portion of the cam 20 with the end of the arm 25 on said rocker member. Shortly after the rocker member 23 starts to move, the detent portion 33 of the spring 32 snaps over the free end of the arm 26 into engagement with the rear side thereof and urges the rocker member rapidly about its pivotal axis toward the position shown in FIG. 2. During clockwise pivotal movement of the rocker member, the latchbolt holdback member 34 is shifted rearwardly relatively to the stud 46 and at the same time is caused to pivot in a counterclockwise direction relatively to said rocker member through coaction of the cam surface 4@ with the stud 46 under the inliuence of the spring 47. The free end portion of the holdback member thus moves downwardly and rearwardly during pivotal movement of the rocker until the stop surface 39-a thereon engages the front face 15-a of the foot 15 on the latchbolt, as shown in FIG. 2, whereupon further movement of the holdback member and the rocker is prevented. In this position of the holdback mechanism, the resultant forces acting on the holdback member 34 are sufficient to overcome the bias of the latchbolt return spring 11 and the latchbolt is therefore retained in retracted position after the cam 20 is returned to its normal position to permit withdrawal of the key from the key plug 21.

It will be noted from FIG. 2 that the free end of the holdback member 34 engages the front face of the foot 15 before the arm 25 of the rocker member engages the stop pin Si). I have designed the holdback mechanism in this way to compensate for tolerance variations in the parts and for additional reasons which I will presently reveal.

When the rocker member 23 is disposed in the position shown in FIG. 2, which corresponds to the latchbolt holdback position of the holdback member 34, the upper edge of the pad 29 on the arm 26 is disposed in the path of the cam 20. Therefore, in order to release the latchbolt to permit its return to projected position, it is only necessary to rotate the cam 20 in a counterclockwise direction, as Viewed in FIG. 2, to move the rocker toward the position shown in FIG. 1, through engagement of said cam with the arm 26. As the rocker member is pivoted to the left, the latchbolt holdback member is shifted forwardly relatively to the stud 46 and at the same time is caused to pivot in a clockwise direction against the tension of the spring 47 through engagement of the cam surface 40 with the periphery of said stud 46. Thus, the free end of the finger 3S is lifted out of engagement with the foot 15. The latchbolt will, of course, follow the holdback member until said free end of the finger 3S moves out of engagement with the foot 15, whereupon the spring 11 will return the latchbolt to fully projected position.

As pointed out above, the rocker member 23 forms part of the conventional dogging mechanism of the illustrated door lock and, although said rocker member is conveniently utilized in the latchbolt holdback means of the present invention, its original function in the clogging mechanism is unaffected. In the extreme left-hand position of the rocker member shown in FIG. l, the dogging means of the lock is engaged with the outer rollback and prevents retraction of the latchbolt from the outer side of the door. When the clogging means is disengaged from the outer rollback, the rocker member occupies its extreme right-hand position, shown in FIG. 5, wherein the arm 25 thereof is engaged with the stop pin 30. From a comparison of FIGS. 2 and 5, it will be noted that the latter position of the rocker is slightly to the right of the position which it occupies when the latchbolt holdback member is engaged with the front face 15-a of the foot 15 on the latchbolt. Consequently, the holdback member 34 is disposed slightly rearwardly of its normal latchbolt holdback position, as shown in full lines in FIG. 5, and its free end portion 39 lies in the rearward travel path of the foot 15 on the latchbolt. As the latchbolt moves rom projected to retracted position, the upper edge 15-b of said foot 15 will engage the cam surface 4041 and pivot the latchbolt holdback member in a clockwise direction to the position shown in dotted lines in FIG. 5. However, since the free end 39-a of the holdback member is disposed rearwardly of the front face 15-a of said foot, even in the extreme rearward positionof the latchbolt illustrated in dotted lines, engagement of the holdback member with the latchbolt is precluded and the latchbolt is free to return to projected position in the usual manner. As the latchbolt returns to projected position, the upper edge IS-b of said foot will move out from under the cam surface 4a thus permitting the latchbolt holdback member to pivot back to its full line position under the influence of the spring 47.

When the rocker member is in its extreme right-hand position illustrated in FIG. 5, the latchbolt holdback member 34 may be moved into holdback engagement with the latchbolt by first moving said latchbolt to its fully retracted position. In this position of the latchbolt, the holdback member 34 will be retained out of holdback position by the retaining surface defined by the upper edge ILS-b of the foot 15 as shown in dotted lines in FIG. 5. The rocker member 23 is then pivoted in a counterclockwise direction, through key operation of the cam 26, until the free end of the finger 39 rides off of the edge l5b of said foot, whereupon the spring 47 will urge the holdback member in a counterclockwise direction and into holdback position as shown in dotted lines in FIG. 6. This method of operation, however, requires careful and precise control of the key and it is therefore more likely that the rocker member will be moved to a position such as that shown in full lines in FIG. 6 wherein the holdback member is supported on the stud 46 and the free end 39-a thereof is disposed forwardly of the face of the foot 15. Thus, when the cam is returned to its normal position, the spring 32 will pivot the rocker member in a clockwise direction to cause movement of the holdback member into latchbolt holdback position, as shown in dotted lines in FIG. 6, through coaction of the cam surface 40 and the stud 46 under the inuence of the spring 47. The latchbolt holdback member and the rocker member then occupy the same positions as illustrated in FIG. 2, and may be actuated to release the latchbolt as previously described.

It will be understood by those skilled in the art that the latchbolt holdback means of my invention may be used in other types of door locks than that shown. While I have illustrated herein one preferred embodiment of the present invention, it will be apparent that numerous changes and modifications may be made therein and I do not, therefore, desire to limit the invention to the exact environment, construction and operation shown and described. Accordingly, all suitable modifications and equivalents may be resorted to that fall within the scope of the invention as claimed.

What I claim as novel is as follows:

1. In a door lock including a casing, a latchbolt mounted in said casing for movement forwardly therein to projected position and rearwardly to retracted position, spring means biasing said latchbolt forwardly toward projected position and a forwardly facing abutment surface on said latchbolt; the combination of: a carrier member pivotally mounted in said casing for movement between a rst position and a second position, a latchbolt holdback member pivotally mounted on said carrier member and being movable bodily relatively to said latchbolt during pivotal movement of said carrier member between its said first and ,second positions, said latchbolt holdback member having a stop surface thereon opposed to said abutment surface and being pivotally movable relatively to said carrier member between a normal position wherein said stop surface is disposed out of the path of said abutment surface and a latchbolt holdback position wherein said stop surface is engaged with said abutment surface whereby to hold said latchbolt in retracted position against the bias of said spring means, means including cooperative cam surfaces on said casing and said holdback member for caus- `ing pivotal movement of said holdback member into and out of latchbolt holdback position upon pivotal movement of said carrier member between its said rst and second positions and means associated with said lock for actuating said carrier member.

2, In a door lock including a casing, a latchbolt mounted in said casing for movement forwardly therein to projected position and rearwardly to retracted position, spring means biasing said latchbolt forwardly toward projected position and a forwardly facing abutment surface on said latchbolt; the combination of: a carrier member pivotally mounted in said casing, a latchbolt holdback member pivotally mounted on said carrier member and being movable thereby releatively to said latchbolt, said latchbolt holdback member having a stop surface thereon opposed to said abutment surface and being pivotally movable relatively to said carrier member between a first position wherein said stop surface is disposed out of the path of said abutment surface and a latchbolt holdback position wherein said stop surface is engaged with said abutment surface whereby to hold said latchbolt in retracted position against the bias of said spring means, means biasing said holdback member toward latchbolt holdback position, retaining means engageable by said holdback member for preventing movement thereof into latchbolt holdback posion, said holdback member being movable out of engagement with said retaining means through pivotal movement of said carrier member and into latchbolt holdback position under the influence of said biasing means, and manually operable means associated with said lock for actuating said carrier member.

3. In a door lock including a casing, a latchbolt mounted in said casing for movement forwardly therein to projected position and rearwardly to retracted position, spring means biasing said latchbolt forwardly toward projected position and a forwardly facing abutment surface on said latchbolt; the combination of: a carrier member pivotally mounted in said casing for movement between a first position and a second position, a latchbolt holdback member pivotally mounted on said carrier member and having a portion containing a stop surface opposed to the abutment surface on said latchbolt, said latchbolt holdback member being pivotally movable relatively to said carrier member between a normal position wherein said stop surface is disposed out of the path of said abutment surface and a latchbolt holdback position wherein said stop surface is engaged with said abutment surface whereby to hold the latchbolt in retracted position, a guide member in said casing relatively to which said holdback member is moved upon pivotal movement of said carrier member between its said first and second positions, a cam surface on said holdback member engageable with said guide member and arranged to guide said holdback member from normal position to latchbolt holdback position when said carrier member is pivoted from its first position to its second position and from latchbolt holdback position to normal position when said carrier member is pivoted from its second position to its irst position, and means associated with said lock for pivoting said carrier member between its said positions.

4. In a door lock including a casing, a latchbolt mounted in said casing for movement forwardly therein to projected position and rearwardly to retracted position, spring means biasing said latchbolt forwardly toward projected position and a forwardly facing abutment surface on said latchbolt; the combination of: a carrier member mounted in said casing for pivotal movement in opposite directions, a latchbolt holdback member pivotally mounted on said carrier member and having a portion containing a stop surface opposed to the abutment surface on said latchbolt, said holdback member being pivotally movable relatively to said carrier member between a normal position wherein said stop surface is disposed out of the path of said abutment surface and a latchbolt holdback position wherein said stop surface is engaged with said abutment surface whereby to hold the latchbolt in retracted position, a guide member in said casing relatively to which said holdback member is moved during pivotal movement of said carrier member, a cam surface on said holdback member engageable with said guide member and arranged to guide said holdback member from its normal position to its latchbolt holdback position when said carrier member is pivoted in one direction and from its latchbolt holdback position to its normal position when said carrier member is pivoted in the opposite direction, means for biasing said holdback member about its pivot in a direction to urge said cam surface into engagement with said guide member, and means associated with said lock for pivoting said carrier member in either of said directions.

5. In a door lock including a casing, a latchbolt mounted in said casing for movement forwardly therein to projected position and rearwardly to retracted position, spring means biasing said latchbolt forwardly toward projected position and an abutment on said latchbolt having a first abutment surface facing forwardly thereof and a second abutment surface extending rearwardly from said first abutment surface; the combination of: a carrier member pivotally mounted in said casing for movement between a first position and a second position, a latchbolt holdback member pivotally mounted on said carrier member and being movable rearwardly when said carrier member is pivoted from its first to its second position and forwardly when said carrier member is pivoted from its second to its first position, said holdback member having a portion containing a stop surface opposed to said first abutment surface on said latchbolt and being pivotally movable relatively to said carrier member between a normal position wherein said stop surface is disposed out of the path of said first abutment surface and a latchbolt holdback position wherein said stop surface is engaged with said first abutment surface whereby to hold the latchbolt in retracted position, a guide member in said casing relatively to which said holdback member moves during pivotal movement of said carrier member, a cam surface on said holdback member engageable with said guide member and arranged to guide said holdback member from its normal to its latchbolt holdback position when said carrier member is pivoted from its first to its second position and from its latchbolt holdback to its normal position when said carrier member is pivoted from its second to its first position, means biasing said holdback member about its pivot to urge said cam surface into engagement with `said guide member, said carrier member being pivotally movable to a third position when said latchbolt it projected and wherein said holdback member is disposed rearwardly of its latchbolt holdback position to prevent engagement thereof with said first abutment surface when said latchbolt is retracted, said portion of the holdback member being disposed in the path of said second abutment surface on said latchbolt in the third position of said carrier member, said holdback member being adapted to pivot away from said guide member upon engagement of said portion by said second abutment surface to permit movement of said latchbolt from projected to retracted position, and means associated with said lock for pivoting said carrier member to its said positions.

6. ln a door lock including a casing, a latchbolt mounted in said casing for reciprocable movement along its longitudinal axis between a forward projected position and a rearward retracted position, spring means biasing said latchbolt forwardly toward projected position and a forwardly facing abutment surface on said latchbolt; the combination of a carrier member mounted in said casing for pivotal movement in opposite directions about an axis extending transversely to the axis of said latchbolt, a latchbolt holdback member mounted on said carrier member for pivotal movement about an axis spaced from and extending substantially parallel to the pivotal axis of said carrier member whereby said holdback member is bodily moved generally forwardly and rearwardly in said casing upon pivotal movement of said .carrier member in opposite directions, said holdback member having a portion at its rearward end containing a stop surface opposed to the abutment-surface on said latchbolt and being pivotally movable relatively to said carrier member between a normal position wherein said stop surface is disposed clear of said abutment surface and a latchbolt holdback position wherein said stop surface is engaged with said abutment surface and holds the latchbolt in retracted position, a guide member in said casing extending generally parallel to the pivotal axis of said holdback member and relatively to which said holdback member is moved during pivotal movement of said carrier member, a cam surface on said holdback member engageable with said guide member and arranged to guide said holdback member into and out of latchbolt holdback position, spring means yieldingly biasing said holdback member about its pivotal axis in a direction to urge said cam surface into engagement with said guide member, and manually operable means associated with said lock for pivoting said carrier member in opposite directions to effect movement of said holdback member into and out of latchbolt holdback position.

7. In a door lock including a casing, a latchbolt mounted in said casing for reciprocable movement along its longitudinal axis between a forward projected position and a rearward retracted position, spring means biasing said latchbolt forwardly toward projected position and an abutment on said latchbolt having a forwardly facing abutment surface; the combination of: a carrier member mounted in said casing for pivotal movement between a first position and a second position about an axis extending transversely to the axis of said latchbolt, a latchbolt holdback member mounted on said carrier member for pivotal movement in opposite directions about an axis yspaced from and extending substantially parallel to the pivotal axis of said carrier member, said latchbolt holdback member being bodily moved generally forwardly and rearwardly in said casing upon pivotal movement of said carrier member between its said first and second positions, said holdback member having a finger portion at its rearward end containing a stop surface opposed to the abutment surface on said latchbolt and being pivotally movable relatively to said carrier member into and out of a latchbolt holdback position wherein said stop surface is engaged with said abutment surface to hold said latchbolt in retracted position, a spring biasing said holdback member toward latchbolt holdback position, said holdback member being disposed rearwardly of its latchbolt holdback position when said carrier member is in its said first position and in a position wherein said finger portion is engageable by said abutment to prevent movement of said holdback member into latchbolt holdback position during normal retraction and projection of said latchbolt, said finger being movable forwardly and out of engagement with said abutment when said carrier member is pivoted toward its said second position with said latchbolt in retracted position to thereby permit movement of said holdback member into latchbolt holdback position under the influence of said spring, cooperative cam means in said casing and on said holdback member for urging said holdback member out of latchbolt holdback position upon further movement of said carrier member toward its said second position, and manually operable means associated with said lock for operating said carrier member.

References Cited in the file of this patent UNITED STATES PATENTS 1,168,725 Hurd Jan. 18, 1916 

1. IN A DOOR LOCK INCLUDING A CASING, A LATCHBOLT MOUNTED IN SAID CASING FOR MOVEMENT FORWARDLY THEREIN TO PROJECTED POSITION AND REARWARDLY TO RETRACTED POSITION, SPRING MEANS BIASING SAID LATCHBOLT FORWARDLY TOWARD PROJECTED POSITION AND A FORWARDLY FACING ABUTMENT SURFACE ON SAID LATCHBOLT; THE COMBINATION OF: A CARRIER MEMBER PIVOTALLY MOUNTED IN SAID CASING FOR MOVEMENT BETWEEN A FIRST POSITION AND A SECOND POSITION, A LATCHBOLT HOLDBACK MEMBER PIVOTALLY MOUNTED ON SAID CARRIER MEMBER AND BEING MOVABLE BODILY RELATIVELY TO SAID LATCHBOLT DURING PIVOTAL MOVEMENT OF SAID CARRIER MEMBER BETWEEN ITS SAID FIRST AND SECOND POSITIONS, SAID LATCHBOLT HOLDBACK MEMBER HAVING A STOP SURFACE THEREON OPPOSED TO SAID ABUTMENT SURFACE AND BEING PIVOTALLY MOVABLE RELATIVELY TO SAID CARRIER MEMBER BETWEEN A NORMAL POSITION WHEREIN SAID STOP SURFACE IS DISPOSED OUT OF THE PATH OF SAID ABUTMENT SURFACE AND A LATCHBOLT HOLDBACK POSITION WHEREIN SAID STOP SURFACE IS ENGAGED WITH SAID ABUTMENT SURFACE WHEREBY TO HOLD SAID LATCHBOLT IN RETRACTED POSITION AGAINST THE BIAS OF SAID SPRING MEANS, MEANS INCLUDING COOPERATIVE CAM SURFACES ON SAID CASING AND SAID HOLDBACK MEMBER FOR CAUSING PIVOTAL MOVEMENT OF SAID HOLDBACK MEMBER INTO AND OUT OF LATCHBOLT HOLDBACK POSITION UPON PIVOTAL MOVEMENT OF SAID CARRIER MEMBER BETWEEN ITS SAID FIRST AND SECOND POSITIONS AND MEANS ASSOCIATED WITH SAID LOCK FOR ACTUATING SAID CARRIER MEMBER. 